Artificial limb



A. PRINGLE AND T. S. KIRK.

ARTIFICIAL LIMB.

APPLICATION FILED AUG.6, I920.

Patented Nov. 22, 1921.

2 SHEETS-SHEET I.

A. PRINGLE AND .T. s. KIRK.

ARTIFICIAL LIMB.

APPLICATION FILED AUG.6, 1920.

1 ,397,654, Patented Nov. 22, 1921.

2 SHEETSSHEET 2.

I'- I .II"

UNITED STATES PATENT OFFICE.

ARTIFICIAL LIMB.

Specification of Letters Patent. Patented NOV.22, 1921.

Application filed August 6, 1920. Serial No. 401,606.

T 0 all whom it may concern Be it known that we, ALEXANDER PRINGLE, of12 Springdale Gardens, Belfast, Ireland, and THOMAS SINCLAIR KIRK, of 21University Square, Belfast, Ireland, both subjects of the King of GreatBritain and Ireland, have invented certain new and useful ImprovementsRelating to Artificial Limbs, of which the following is a specification.

This invention relates to joints for artificial limbs, its object beingto provide improvements therein.

According to the invention the joint, which is particularly adapted foruse as an elbow but may be used for other purposes, consists of acombination of oppositely dis posed toggles which are, or are adapted tobe, connected with the limb. Locking means may be provided in connectionwith the toggles whereby the joint may be locked or secured in differentpositions.

The invention will now be described with reference to the accompanyingdrawings whereon it is shown applied to an artificial arm.

Figures 1 and 1 are side elevations of an elbow joint, in accordancewith the invention, in different positions and drawn to differentscales.

Fig. 2 is an elevation looking in the direction of the arrow at Fig. 1.

Fig. 3 is an elevation of an artificial arm having the elbow jointillustrated by Figs. 1 and 2 applied thereto.

Fig. 4 shows an arm with a similar construction of elbow joint buthaving an upper arm so made and connected with the elbow joint and withthe shoulder that the locking of the elbow joint also effects a lockingof the shoulder joint.

Figs. 5 and 6 are side and end elevations, respectively, of amodification of the elbow joint shown in Figs. 1 and 2.

Referring to the drawings The elbow joint shown at Figs. 1 and 2comprises three cross frames at, b, and. 0 which, in the example shown,are of cruciform shape (see particularly Figs. 2 and 6). The crossframes a and b are connected by pairs of crossed links (Z and 7 whilethe frames 7) andc are connected by pairs of crossed links 9 and it,said links constituting pairs of opposed toggles. The connection of thelinks (Z, f, g, andh, with the frames a, b, and c is made by means ofpivot pins so that each link has freedom of movement about two of thelinks, namely (l and h, are pro-- vided with segmental projections (Zand h having series of teeth or indents therein and a locking bolt Z ismounted in slots in the cross frame Z) in such manner that it can becaused to engage the teeth of the segments- (Z and ii The bolt Z isunder the constant pressure of a spring Z (Fig. 2) and has a projectionZ thereon so arranged that when it is placed above a projection or pin mon the frame Z) (as shown at Fig. 2 of the draw ings) the bolt willengage the teeth in the segments and when the projection Z is placedbelow the pin on the bolt will be held out of engagement with saidteeth. Temporary disengagement may be effected by pressing the bolt Z,against the action of the spring Z until the notch or recess Z thereinregisters with the toothed segments.

Instead of the locking arrangement hereinbefore described, we may useanother looking arrangement in which the locking is effected byfrictional action. Such an ar-. rangement is shown at Figs. 5 and 6 andcomprises a pin 2' which extends between the links at each side of thejoint and has a fiber distance piece 71 thereon between said links. Thepinz' extends beyond the links at each side and engages slotsb therein.and also engages slots 72" in the. center cross frame 6, so that saidframe Z) is maintained in a-central position. Between the links and thecross frame 6 are two fiber stoppers or washers and i loose on the'pini. A metal washer i on the outer side of the cross frame I) has a camface i and is loose on the pin 'but so engages with the cross frame thatit is prevented from turning with the pin 2' and is adapted to be actedupon by a cam face i secured to or forming part of the pin 2'. The pin2' is provided with a lever grip i and an adjustable nut to compensatefor wear between the parts. The arrangement is such that when the pin 71is turned in one direction, the cam face i thereon will co-act with thecam face 2' of the washer i and produce a wedging or jamming action onthe fiber washers i and i in opposite directions and cause same to lockthe links, at both sides of the joint, against the fiber distance piece'5 When the pin i is turned in the other direction the links will befreed from this locking action and will thus allow free movement of thejoint.

The frame a is connected with. a metal end 1?.- of the socket of theupper arm 0, (see Fig. 3) and, as shown at Fig. 1 the frame a and withit the whole of the elbow and lower arm etc., can be turned relativelyto the upper arm 0. For this purpose slots n are provided in the endfitting n of the upper arm with which pins a on the frame a engage. Oneof the pins 0& is fitted with a screw clamp a whereby the frame a can beclamped to the end fitting at when it is desired to prevent any turningmovement between the elbow and the upper arm.

A curved plate or member 79 isshown secured to the frame I). This curvedplate 1) holds out the sleeve of any garment worn by the wearer of theartificial arm, when the arm is bent. I

A modified construction of upper armvis shown at Fig. 4. In this casethe links (Z and f from the frame I) are carried up to the shoulder asshown. This construction does not give quite such an extensive turningmovement of the elbow but it gives simultaneous locking of the elbow andshoulder joints.

Having now fully described our invention what we claim and desire tosecure by Letters Patent is:

1. In an artificial limb, a joint comprising a plurality of cross framesand oppositely disposed toggles pivotally connected thereto.

2. An artificial limb joint comprising a plurality of frames, oppositelydisposed toggles pivotally connected therewith and means for lockingsaid frames against relative movement. 7

3. In an artificial limb, a oint comprising a frame, oppositely disposedtoggles connected with said frame and limb and frictional means forlocking the frame and said slotted links and one ofthe frames to lockthe frames against relative movement.

a I 5. An artificial limb-joint comprising a plurality of frames, one ofwhich is slotted, links, certain of which are slotted, connecting saidframes and means adapted to co-act with said slotted links and frame tolockthe joint. 7

6. An artificial limb joint comprising a plurality of frames, one ofwhich is slotted, links, certain of which are slotted, connecting saidframes and a bolt mounted in the slots in said links and frames andadapted to lockthe joint.

7. An artificial limb joint comprising a plurality of frames ofcruciform shape and links ivotally connected therewith.

8. n artificial limb joint comprising three cross frames, crossed linkspivotally connected therewith and means for locking said frames againstrelative movement. 9. An artificial limb joint comprising a plurality offrames, links connecting said frames, a bolt in connection with a: frameand certain of said links and cam means for effecting an axial movementof said bolt and the locking of the joint. p

10. An artificial limb joint comprising a plurality of frames,links'connecting said frames, a bolt in connection with a frame andcertain of said links, cam means for effecting an axial movement of saidbolt and the locking of the joint and means for adjusting said bolt tocompensate for weary 11. An artificial limb joint comprising a pluralityof frames, crossed links pivotally connected with said frames, and acurved member to prevent sagging of the clothes of the wearer when thejoint is bent.

12. In an artificial limb, a joint comprising a plurality of frames andoppositely disposed diagonal links connecting same,.a second joint andmeans for simultaneously locking both joints. V i

In testimony whereof we aiiix our signatures in presence of twowitnesses.

ALEXANDER PRINGLE. THOMAS SINCLAIR KIRK.

Vitnessies 7 ANDREW HAMILTON, HARRY WALTER ALLsoP.

